30 October 2023

If you’ve only seen Jack O’Lantern mushrooms (Omphalotus olearius) during the day you may have thought they were named for their orange pumpkin-like color.

Instead they are aptly named because they glow green in the dark, as shown in the top photo.

Perhaps, like Armillaria mushrooms, Omphalotus olearius is bioluminescent because of the chemical reaction they use to consume decaying wood. Armillaria‘s chemical reaction glow is described in this vintage article on foxfire.

Jack O’Lantern is one of only about 112 species of fungi that are bioluminescent. Find out more at 10 Bioluminescent Mushrooms That Glow in the Dark.

p.s. Never eat Jack O’Lantern (Omphalotus olearius). It is poisonous!

(photos from Wikimedia Commons & Kate St. John; click on the Wiki caption to see the original)

2 October 2023

In September birders lurk near devil’s walking stick in Frick Park because the plants attract birds on migration. Crawling with tiny insects and full of fruit, devil’s walking stick is often swarmed with visiting warblers, cedar waxwings and robins. But is it really devil’s walking stick (Aralia spinosa)? Or is it the invasive look-alike Japanese angelica (Aralia elata)? Or even worse, is it a hybrid?

I didn’t know about this possibility until Dave Brooke posted photos of two warblers on devil’s walking stick. The first was a Tennessee warbler, at top, followed by a Cape May warbler, below, that landed on the same perch in the same pose just 25 seconds later.

Anne Swaim responded to Dave’s post saying “Probably Aralia elata, the Japanese Angelica. Great bird attractant (but really invasive.) Same genus as the native Devil’s walking stick.”

Native to eastern Russia, China, Korea and Japan, Japanese angelica (Aralia elata) was brought to the U.S. as an ornamental plant. It’s well known in eastern Pennsylvania and New York state because those areas are outside Aralia spinosa‘s native range. Pittsburgh is on the border though, so I always assumed I was looking at the native plant.

It’s so hard to tell them apart that New York Botanical Garden posted this guide to invasive look-alikes. Here’s a screenshot from the Aralia sp pages:

Their Quick ID is helpful for non-botanists like me.

Quick ID of Aralia elata (invasive alien):

1. Leaf veins: Main lateral veins running all the way to the tips of teeth at the leaf margin.
2. Inflorescence: Inflorescence shorter, typically 30–60 cm long, and WITHOUT a distinct central axis (often wider than long, with base usually surrounded by and even overtopped by foliage).

Quick ID of Aralia spinosa (native):

1. Leaf veins: Main lateral veins branching and diminishing in size before reaching the leaf margin (smaller branching veins may run to the tips of teeth)
2. Inflorescence: Inflorescence longer, often 1–1.2 m long, WITH a distinct central axis (typically longer than wide, base usually elevated above foliage).

— Mistaken Identity? Invasive Plants and Their Native Look-Alikes, A Guide for the Mid-Atlantic (posted by NY Botanical Garden)

I tried to identify the plants at Frick by looking at the leaves but it’s very hard to do. The easiest way is by looking at the inflorescence — the tower of flowers.

Japanese angelica’s (Aralia elata) inflorescence basically lies flat. It does not have a central stem and the leaves may cover some of the flowers. Here’s Japanese angelica at Frick.

Devil’s walking stick’s (Aralia spinosa) inflorescence stands tall above the leaves on a central stalk.

Now I’ve started looking at all the Aralias and asking: Which one are you?

You might know of a stand of a devil’s walking stick you’d like to examine too. To figure out its identity download the Mistaken Identity guide at nybg.org ==> https://www.nybg.org/files/scientists/rnaczi/Mistaken_Identity_Final.pdf

Also see Tom Potterfield’s Flickr album with photos of both species.

Meanwhile, for the sake of the warblers I am deciding not to get excited that these plants are alien. The birds love them so much and I love the birds so …

p.s. Read more about Japanese angelica’s invasive qualities at the Brandywine Conservancy: Invasive Species Spotlight: Japanese Angelica Tree (Aralia elata). Here’s where it occurs in the U.S. Yes, in Allegheny County. Wonder who planted it.

(photos by Dave Brooke, nybg.org, Kate St. John and Tom Potterfield. Click the links in the captions to see the originals)

12 September 2023

Why do some plants have the suffix “-wort” in their names?

The suffix “-wort” simply means “plant.” In earlier centuries, plant common names often referred to physical characteristics, resemblance, or recommended medicinal uses.

— Univ of Wisconsin-Madison Arboretum: Gardening with Native Plants: Worts and Weeds, pt. 1

Here are some recently blooming “-worts.”

Purple milkwort (Polygala sanguinea), above, is native to North America. “The genus name Polygala comes from the ancient Greek “much milk”, as the plant was thought to increase milk yields in cattle.” I have no idea if this works.

Mugwort (Artemisia vulgaris), related to ragweed, is used in cooking and has been used medicinally. It has a bitter flavor. Why “mug”? I don’t know.

Pilewort (Erechtites hieraciifolius) is a member of the Aster family that grows easily in disturbed soil. Quirky Science says the “reported uses include the treating of hemorrhage, dysentery, skin diseases, and cholera. It is a purgative and emetic. The name suggests it is good in treating piles (hemorrhoids).”

St. Johns wort (Hypericum perforatum), imported from Europe, is so-named because it blooms in June and was traditionally harvested on St. John’s Day, June 24, to adorn homes and ward off evil. It is an herbal treatment for depression and has been planted nearly worldwide.

(photos by Kate St. John)

Here’s a pretty plant, an invasive alien, that I’ve not seen in Pittsburgh but is easy to find in Lancaster County, PA where I took this picture.

Beefsteak plant (Perilla frutescens) is a member of the mint family native to Southeast Asia and the Indian highlands and is grown as a crop for Japanese, Korean and Chinese cuisine. Its common names include shiso and Korean perilla. The “beefsteak” name was coined because the darkest varieties have leaves as red as meat. The wild plants I saw in Lancaster County had green leaves and dark red stems.

Perilla frutescens is widely cultivated in Asia as an edible plant but it has downsides including contact dermatitis from touching the leaves and anaphylaxis after consuming a large amount of seeds. Those who cultivate it know what to do but the rest of us should be cautious.

Brought to the U.S. as an ornamental beefsteak plant escaped to the wild and is now invasive in six states from Pennsylvania to Tennessee. The plant is always toxic to cattle, horses and other ruminants including white-tailed deer.

Since deer don’t eat it, it may have been touted as a “deer resistant” plant at the nursery but don’t buy it! This plant spreads way too easily.

(credits are in the captions with links where applicable)